1. Field of the Invention
Embodiments disclosed herein generally relate to an apparatus and a method for placing a substrate substantially flush against a substrate support in a processing chamber.
2. Description of the Related Art
As the demand for larger flat panel displays (FPDs) and larger solar panels continues to grow, so does the size of the substrates used in forming the FPDs and solar panels. With an increase in substrate size, the chambers used to process the substrate increase as well. It is not uncommon for chambers to be sized to process a substrate having a surface area of greater than about two square meters.
Deposition processes such as plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and chemical vapor deposition (CVD) may be performed to deposit desired layers onto the large area substrates. Removal processes such as etching, either plasma or liquid, may also be performed on the large area substrates as well.
For semiconductor wafer processing, the wafers may have a diameter of about 200 mm or about 300 mm. It is believed that the next generation of semiconductor wafers will be about 400 mm in diameter. Thus, the surface area for semiconductor wafers is significantly smaller than the surface area for large area substrates.
Scaling up the size of semiconductor wafer processing chambers to the size used to process large area substrates is not simple. Many complications may arise such as maintaining a uniform plasma within the chamber, providing sufficient power to generate a plasma in the chamber, and cleaning the chamber to name only a few. Additionally, semiconductor wafers are generally round substrates while many large area substrates are polygonal or rectangular. Scaling up a round processing chamber to process a large area rectangular or polygonal substrate may not work.
Therefore, there is a need for a processing chamber to process large area substrates.